Intro:
The Bible and why it's reliable
The logic of Christianity
The source of Christianity
The adaptability of the gospel
Acts of God
The uniqueness of the Bible and why it's reliable
The Bible (holy writings of Christianity) is unique from other writings in that God didn't himself write anything in the Bible. He instructed the prophets what to say, and inspired many other books, but He allowed the personal style of the authors to be present.
Also, the fact that the 66+/- books of the Bible have 40+/- authors separated by large intervals of time at parts, yet clearly comes together with a legible, reasonable message from God is amazing. You've probably heard the watchmaker analogy in "defense" of Intelligent Design. In this case we have a true example of this analogy. It takes quite a bit of effort to claim that somehow, the odds were so in favor of this event that the compilation of the 66+ books resulted in the Bible we have now. Free of contradictions.
Mind you, I agree there are apparent contradictions- ones that seem contradictory but upon consideration aren't substantial or contradictory. For instance, numbers (especially larger ones) mentioned are rarely ever important. Due to the method of counting in the ancient times, and even with printing presses, scribal errors in numbers had high probabilities. But unless the number of golden spoons in Israel's camp after the return from Babylon determines my eternal fate, it isn't relevant to theology.
Now it is important to take into consideration the methods of choosing what was "biblical"- what should be in the Bible. In the Old Testament, Jews had standards as to whether or not prophets could be trusted. Not everybody claiming to be a prophet was trusted. They tested the prophecies and if they proved true, they'd listen to those prophets (continually expecting them to be correct, if in fact God was talking to them of course). False prophets got punishments akin to blasphemy. Jews were serious about their religion, and if you claimed God was speaking o you, and prophesied something false, you 1) lied. 2) claim God lies.
In the New Testament, the general criteria was that you had to either be an apostle, or have witnessed Jesus Christ and his resurrection. Some people question Paul's authority, however elsewhere He is mentioned as an allstle by others, and his humility in calling himself "the lowest of the apostles" shows that he didn't mind if he wasn't considered an apostle as long as he could spread the gospel of Jesus Christ. It wasn't about fame for him, but the message of Christ, Christianity. More particular criterion consist of having to be authored prior to the end of the first century, to ensure not only that the first criteria is met, but also so that we have as many accurate accounts as possible. Even though the canon of the Bible was made about 200 or 300 years after Christ (I believe, I can't remember the actual date), there are records of the early church in the writings of the Early Church Fathers. These are early Christians whose writings explained and defended Christianity. These generations were subsequent to the apostles, and were taught all that the apostles knew.
The logic of Christianity
The theology of Christianity is free from errors. This is due to the lack of real contradictions in the Bible. The theology of Christianity also resonates with the consciousness of humanity. We all have a desire for justice in some form, love, community, mercy even though that's never up to us, and truth. Christianity encourages and teaches all of these things.
In fact, Humanism in America is based on the morals and values of Christianity, whether they know this or not.
God encourages His followers through a prophet and an apostle, "come, let Us reason together" and "be ready to give an answer to anyone who ask about the hope/faith you have," respectively. God doesn't want us to be foolish or ignorant; He wants us to know truth because He is Truth incarnate. Truth leads to Christ, in other words. Note that a person who views the Bible literally as is isn't wrong. If you believe an analogy as is, you also (passively) believe the truth analogies. So if anything in the Bible that is analogy is believed as literal, this person is correct. For instance O see both sides of the debate of Genesis being literal or figurative. If it's literal, God created all things, and we fell into sin a short period of time after creation. If it's not literal, God created all things and we fell quite a bit after creation. While this can be misunderstood as a logical fallacy of shifting goalposts, Jesus said He spoke in the gospels in parable so the message would be hidden. His goal was to inspire us to seek God for understanding. I believe He may have done the same with the rest of the Bible, consistently. So I personally have no inclination either way in the debate. I merely hold what the Bible says and answer the questions of evolution as science accepts.
The source of Christianity
Evident in the name, Christ is the focus. Our religion revolves around Him and obeying Him. But it goes deeper to that. We love Him because He first loved us, and we also obey Him out of love rather than obligation or force. It must be said that His will is perfect and pleasing.
Jesus created a movement. God's interaction with man was never to create a religion or govern our lives. Ever since our first ancestors, God has made it clear that He made us to be in community with Him.
The resurrection. Christ resurrected in the flesh and walked amongst a large group and interacted with the apostles. This large group IIRC was over 500. The churches that were told this had the ability to visit these people if yet wished, to verify the claims, so that it was staged or a hallucination are week arguments. To get 500 plus people stupored enough to see a man walk among them - and it be the same man - is a pretty strong drug and I think would have killed them. While an appeal to a majority doesn't prove anything, a claim of this type is pretty hard to combat. Point: "If Christ isn't resurrected, then we are to be the most pitied people. But if He did, then Jesus Christ is who He claimed to be and made a way for us to be liberated from our sin.
The adaptability of the gospel
The gospel - which is that Jesus Christ was God incarnate as a man, who walked among us and lived a life holy and pleasing to God, and died on a cross and rose on the third day- freeing us from the fear of death and the trappings of sin - is culturally adaptable. It relies on an understanding of te Bible, but as it is relevant to all people, every culture can have it's own expression of devotion to Christ. Asians typically meet together in discreet locations because of their strict government, Americans have a freedom to go to a local church and worship God there. All Christians are devoted to evangelism and helping others. The most important commandment is love, and "a religion pleasing to God looks after widows and orphans." Christianity often promises a great future for God's people, but it's also focused on the here and now, and on people in need.
Acts of God
God does work in our world today. The Bible says that all things are held together in Christ. As He is the Creator, it follows that He is the sustainer. (If you make a car, I hope you take care of it if you plan it to run for a long while)
While He has sent messages to prophets, He also guides us in daily life. Christians pray to talk to God and discern His will in their life. This isn't done through audible voices or supernatural signs (for the most part). Usually, God gives us desires, inclinations I one thing over another, and His Spirit to dwell in Christians so that we can understand His will for our life. He gives people who are saved, new and old Christians, new desires they never had when they weren't Christians. Or thoughts they'd never imagined before. Ie. not all people want to become a pastor of any type even after becoming a Christian, but I know I'm called because I have a unique desire and the knowledge and heart necessary to follow God and help others do the same.
Thank you for your time and effort.